Finding the door contacts wire for fitting an alarm.

[Zebedee]

I've been trying to fit an alarm to my caravelle but have got a little stuck wiring in the door contact switches so the alarm will go off when a door is opened.
The instructions state that you need to connect into the wire from the interior light to the door contact switch. Haynes shows a brown/white wire.

The problem i've found is other than wiring it in to the end of the wire at the actual light there doesn't appear to be anywhere else I can access it.
It seems to run down the inside of the windscreen pillar to the door contact and there's not enough slack in the wire to remove the switch and pull the wire out of the hole.

Anyone else managed to do this before that could give me some suggestions?

[Hacksawbob]

The interior lights all wire back to connector B12 on the back of the fuse box. Connector B is the big red plug on the back of the fuse box. It also runs the cig lighter and the stereo, trace it from B12 and you will find 2 connectors where the radio and cig lighter split off. The interior lights positive feed is after this.

[Zebedee]

I've found the positive feed at the plug on the fusebox (its a red wire). Don't suppose it will matter if i connect into that instead of a point between light and switch?

[Oldiebut goodie]

Surely you need the negative as it is this that is switched.

[Hacksawbob]

Yes it is a negative switch... so there will be no voltage to earth unless the light comes on/door opened, there is no difference afaik between the two, in so far as your voltage will change when you open the door (if the courtesy light is set to door open mode!) and the alarm will detect that and set off. Wire it temp into the socket on the connector I mentioned above with an alligator clip or just jam it in there and see if it behaves how you want it too before getting the pliers out.

[California Dreamin]

The door switches are simply a looped earth....so just extend this loop to your extra door switches, simplez.

Martin

[bigherb]

You can get a switch from VW with two terminals just run the alarm wire to the spare terminal.

[Hacksawbob]

http://www.ebay.co.uk/itm/vw-t25-type-2 ... 1283wt_784" onclick="window.open(this.href);return false;

[Zebedee]

I think i've got some of the 2 terminal switches somewhere in my shed. Never thought of that solution.